He's not wrong.
Mick wants more than Leonard can give him and it's been like that for a long time now and he's done his best to just deal with it. To still try and be a partner. To be his partner.

'Deserve' is an odd choice of words and he shifts a little, frown deepening because where Leonard is going with this Mick has no clue.

"A deal," he repeats slowly. "'m not following you here. What are you talking about?"